Advanced SIP settings and encryption indicator (Follow-up from SRTP MR)
The following discussions from !545 (merged) should be addressed:
-
@devrtz started a discussion: (+1 comment) This is how the option for the account currently look like:
@snwh I was wondering if you have any input as to how to describe the currently available options. Specifically I was discussing with @guidog whether naming an option "SRTP" or even "SRTP SDES" would be acceptable (provided that these terms would be adequately described in the help once we have #385 ).
To give some context:
Currently there are only two options:
- Media is unencrypted (plain RTP)
- Media must be encrypted with SRTP (key exchange done with SDES)
In the future I could imagine we want an option whether to use encryption:
- No media encryption
- Media encryption preferred (but unencrypted is still allowed)
- Media encryption mandatory
and another option for what type of media encryption to use. These are ordered from weakest to strongest security guarantees:
- SRTP SDES (key exchange in the signalling: SIP servers/proxies must be trusted; without TLS keys would be sent in the clear!)
- DTLS-SRTP (keys exchanged during DTLS connection establishment/handshake; signalling carries fingerprints of certificates used; SIP Identity mechanism can be used to protect integrity of fingerprints; potentially verify fingerprints with a bunch of emojis like in Matrix or by the peers reading them to each other - this of course assumes that you know the voice of the other end)
- ZRTP (DH key exchange, seems to depend less any security guarantees on the signaling layer [not too familiar with the details yet] and can be used for opportunistic encryption)
Some relevant art
linphone
jami-gnome
Edit
The following would also be useful/necessary in some setups